Vampires

Vampires come in a several different forms. All are soulless undead, but there's a few constant distinctions from general undead:

1) Vampires are contagious. The specific method varies, but all have the option of making a new version of themselves when they kill. This varies from an elaborate ritual involving force-feeding blood into the corpse to 'every kill'.

2) Vampires have control over their 'spawn'. A vampire's spawn are minions, supported by the power of the parent vampire. If the parent vampire remains well fed, and does not make too many span, then the spawn remain as regular minions and have no need to kill directly. However, the spawn have the capability and knowledge of harvesting what they need by killing. Spawn who repeatedly kill will reach a point where they no longer have a connection to the parent, and become free-willed vampires themselves. Likewise, if the parent vampire dies they'll know they're 'on a clock' and go hunting: Those who find enough prey become free-willed vampires; those who don't resume being properly dead once they run out of power.